Key is down parameter is a key code. It uses a name to be "Human readable" and the name is based on the US keyboard layout.
So when you specify "Key W is down", it is the W key in a US layout. For a FR layout it is Z.
To get key name you have 2 functions:
GetKeyName(KeyCode) to get the US layout key name and GetLocalKeyName(KeyCode) to get key name for local layout.
To display the last key pressed in local layout in you example:
+ InputSystem: Key W is down
-> Text: Set text to InputSystem.GetLocalKeyName(InputSystem.LastKeyDown)
InputSystem.LastKeyDown gives the key code of the last key down.
N.B.: I think a On Char Pressed event is missing